Methods and apparatus for doffing and drafting fibrous webs



Jan. 28, 1964 F. KALWAITES METHODS AND APPARATUS FOR DOFFING ANDDRAFTING FIBROUS WEBS Filed Feb. 19, 1960 4 Sheets-Sheet 1 INVENTQR "F'Fawx K14 kI/A/I'ES ATTORNEY Jan. 28, 1964 F. KALWAITES METHODS ANDAPPARATUS FOR DOFFING AND DRAFTING FIBROUS WEBS Filed Feb. 19, 1960' 4Sheets-Sheet 2 Tia-z!- BY flmma A441- ATTORNEY Jan. 28, 1964 F.KALWAITES 3,119,152

METHODS AND APPARATUS FOR DOFFING AND DRAFTING FIBROUS WEBS Filed Feb.19, 1960 4 SheetsSheet 3 H 11" MF M W! H INVENTOR F/PA/VA Kimm -5ATTORNEY 'Filed Feb. 19. 1960 Jan. 28, 1964 F. KALWAITES v -3,119,152

METHODS AND APPARATUS FOR DQFFING AND DRAFTING FIBROUS WEBS 4Sheets-Sheet 4 WLWMU WW u 50 INVENTOR /-7=A/wr A74Z/V/4/7E'S BY flrmm T@144,-

ATTO R N EY United States Patent 3,119,152 METHODfi AND APPARATUS FURDOFFING AND DRAFTKNG "WEBS Frank Kalwaites, Semen/file, Ni, assignor, bymesne assignments, to Johnson & Sohnson, New Brunswick,

N..l., a corporation of New .lersey Filed ifeb. 19, N60, fier. No. 9,969lb Claims. (Cl. 19-41%) The present invention relates to the dofiing orremoving of textile fibers from movable carrier surfaces, such as therotatable doffing cylinder of a card, for example, and more particularlyis concerned With the removing of fibers from such surfaces andthe-simultaneous drafting or drawing thereof to increase the fiberorientation in the long or machine direction of the resulting webcontaining these fibers.

In the processing of textile fibers whereby they are converted from anaturally-occurring, intermatted fibrous mass into relatively uniform,fibrous textile materials such as webs and slivers having a predominantfiber orientation in the long direction thereof, the individual fibersare initially separated and formed into a fibrous web on a card. Thisweb, in which the individual fibers are relatively aligned generally inthe long direction of the web, is doffed or removed from the dofiingcylinder of the card, usually by a rapidly reciprocating dofier comb,and then further processed, as desired or required, such as by beingdrafted or drawn whereby the orientation of the fibers in the longdirection of the web is increased.

During the removal of the fibers from the doffing cylinder by means ofthe reciprocating comb, the fiber orientation or alignment thereof isusually increased to a limited extent say, up to 70 or 75% and,therefore, subsequent drafting or drawing operations are required toincrease the orientation or alignment of the individual fibers in theWeb above such percentages. These subsequent drafting or drawingoperations have had so much orienting or aligning of the fibers to do toproduce the desired highly oriented web that difficulties in theseoperations have ensued.

In accordance with the present invention, individual fibers in a web areremoved from the doffing cylinder of a card, or from some otherrotatable or movable carrier surface, in a manner which simultaneouslyincreases the fiber orientation in the resulting web. In consequence, amore highly oriented web is obtained and subsequent operations toincrease the orientation and alignment of the fibers are minimized andthereby greatly facilitated and expedited.

in a copending patent application Serial Number 9,965, filedsimultaneously herewith on February 19, 1960, there are describedmethods and apparatus for simultaneously dofiing and drafting fibrouswebs by means of a rotatable stripper roll clothed with metallic orfillet clothing adjacent to but spaced from the rotatable surface of acard dofiing cylinder initially carrying the fibrous web. The methodsand apparatus described therein have been employed satisfactorily fordoffing and drafting fibrous webs having long fibers, say from about 1%inches to about 2 /2 inches or more in length. Where the fibrous webs tobe drafted contain shorter fibers, say from about /2 inch to about 1inch in lengt the apparatus of the said copending application does notlend itself to the same general effectiveness in dofiing and draftingthese fibers as it does for the longer fibers. This is due largely tothe absence of the same physical control over the shorter fibers duringthe drafting operation as the machine exercises upon the longer fibers.

The present invention provides novel methods and apparatus particularlyadapted for dofiing and simultaneously drafting fibrous webs containinga wide range of fiber lengths; either the shorter fibers of from /2 inchto 1 inch in length, the longer fibers up to about 2 /2 inches or morein length, or mixtures of such fibers. During doffing and drafting inaccordance with the present invention the machine exercises positivephysical control over the longer fibers and substantially the samephysical control over the shorter fibers. The extent of physical controlover the shorter fibers by the machine of the present invention has notbeen achieved by other machines insofar as is known.

Simultaneous doifing and drafting may be obtained in accordance with thepresent invention by initially providing a carded fibrous Web on amovable carrier surface, such as the dofiing cylinder of a card, andthen positioning a relatively smooth-surfaced endless flexible beltadjacent to but spaced from the clotting cylinder by a predetermineddistance, whereby the carded fibrous web is transferred from the doifingcylinder to the movable belt. This movable belt, being flexible, may betrained over relatively small diameter rods or bars or equivalentelements positioned in close proximity to the movable fiber-carryingsurface so that the moving belt approaches that surface at any desiredangle, and rapidly departs therefrom at any other angle as desired. Thisis to be contrasted to the gradual departure of the surface of acylinder, for example, the radius of which cannot be made too small forphysical strength reasons. The flexible belt, by then cooperating with asecond rotatable or movable surface which presses against the belt andforms a nip therewith, is able to seize the leading ends of the fibersat a point relatively close to the periphery of the first movable orfiber-carrying surface and to draw the fibers in positive fashiontherefrom.

By suitably adjusting the surface linear velocity of the movableflexible belt with reference to the surface peripheral linear velocityof the movable fiber-carrying surface, the movable belt may be made todraw the fibers away from the fiber-carrying surface at any desiredgreater velocity whereby they are drafted or drawn and assume a morehighly oriented or aligned configuration with respect to the long axisof the drafted fibrous Web. Such a more highly oriented web is moresuitable for further processing, as desired or required.

The fibrous web or layer which is processed to form the products of thisinvention may contain natural or synthetic, vegetable, animal or mineralfibers such as cotton, silk, Wool, vicuna, mohair, alpaca, flax, ramie,jute, etc.; synthetic or man-made fibers such as the cellulosic fibers,notably cuprammonium, viscose or regenerated cellulose fibers;cross-linked cellulosic fibers such as Corval and Topel; cellulose esterfibers such as cellulose acetate (Celanese) and cellulose tri-acetate(Arnel); the saponified cellulose ester fibers such as Fortisan andFortisan-36; the polyamide fibers such as nylon 420, nylon 6(polycaprolactam), nylon 66 (hexarnethylene diamine-adipic acid), nylon610 (hexa methylene diamine-sebacic acid), nylon 11 (ll-amino undecanoicacid-Rilsan); protein fibers such as Vicara; halogenated hydrocarbonfibers such as Teflon (polytetrafiuoroethylene); hydrocarbon fibers suchas polyethylene, polypropylene, polybutadiene and polyisobutylene;polyester fibers such as Kodel and Dacron; vinyl fibers such as Vinyonand saran; dinitrile fibers such as Darvan; nitrile fibers such asZefran; acrylic fibers such as Dynel, Verel, Orlon, Acrilan, Creslan,etc.; mineral fibers such as glass, metal; etc.

The lengths of the fibers in the starting fibrous web may vary fromabout /2 inch up to about 2 /2 inches or more in length, depending uponthe particular properties and characteristics required or desired in theresulting fibrous web. If desired, the fibrous layer may have fibersother than those of textile length added thereto.

The amount of such other fibers to be added will depend upon theproperties desired in the final products to be produced from the fibers,and upon how close to the fiber-carrying surface the fibers can begripped for doffing. The amount may vary from about 1 or 2% by weight upto about 100% by weight, but will usually be preferably less than about50% by weight. These other fibers may be of papermaliing length, whichextend from about inch in length down to about ,1 of an inch or less inlength, which shorter fibers normally are not used in conventionalmethods of producing fibrous webs.

Illustrative of these short paperrnaking fibers are the naturalcellulosic fibers such as woodpulp and wood fibers, cotton linters,cotton hull shavings fibers, mineral fibers such as asbestos, glass,rocl-zwool, etc., or any of the hereinbefore-mentioned natural orsynthetic fibers in lengths less than about /2 inch and down to about Aof an inch or less.

The denier of the individual synthetic fibers referred to above ispreferably in the range of the approximate thickness of the naturalfibers mentioned and consequently deniers in the range of from about 1to about are preferred. Where greater opacity or greater covering poweris desired, special fiber deniers of down to about /4 or even about /2may be employed. Where desired, deniers of up to about 5.5, 6, 8, 1O,15, or higher, may be used. The minimum and maximum denier are naturallydictated by the desires or requirements for producing a particularfibrous web, by the machines and methods for producing the same, and soforth.

The weight of the fibrous web or layer of starting material on thedofiing cylinder may be varied within relatively wide limits above apredetermined minimum value, depending upon the requirements of theintermediate or the final products. A single, thin web of fibers, suchas produced by a card and as presented by the doffing cylinder, may havea weight of from about 30 to about 250 or more grains per square yardand may be used in the application of the principles of the presentinvention. Within the more commercial aspects of the present invention,however, web weights on the dofiing cylinder of from about 60 grains persquare yard to about 175 grains per square yard are contemplated.

If heavier web weights are desired for the final Web of highly alignedfibers, such as up to 1800 grains, for example, several individual websof highly aligned fibers produced in accordance with this invention maybe com-- bined into a laminated structure to obtain the desired weight.The product of one doffing and drafting machine may be folded, doubled,tripled, etc., on itself to reach the heavier Weight, or the productsfrom a plurality of dofiing and drafting machines may be used and theindividual products stacked or laminated for a similar purpose.

The invention will be more fully understood from the description whichfollows, taken in conjunction with the accompanying drawings in whichthere are illustrated preferred designs of machines and modes ofoperation embodying the invention. It is to be understood, however, thatthe invention is not to be considered limited to the constructionsdisclosed except as determined by the scope of the appended claims. Inthe drawings:

FIGURE 1 is a simplified, fragmentary, schematic view in elevationshowing the general principles of operation of the present invention;

FIGURE 2 is a simplified, fragmentary, schematic view in elevationshowing in greater detail the structure and operation of one embodimentof the dofiing and drafting mechanism of the present invention;

FIGURE 3 is a simplified, fragmentary, schematic view of a l-inch stripof Web disposed upon the surface of the dofiing cylinder, extendingacross the width thereof at approximately the four oclock position inFIGURE 1, showing a few illustrative individual fibers as seen by 4. onelooking at the surface of the doffing cylinder from the right hand sideof FIGURE 1;

FIGURE 4 is a showing of the same l-inch strip of web upon the surfaceof the doffing cylinder at approximately the eight oclock position inFIGURE 1, showing the same illustrative individual fibers as are seen inFIG- URE 3 except that in this figure they are shown as seen by onelooking at the surface of the doffing cylinder from the left hand sideof FIGURE 1;

FIGURE 5 is a simplified, fragmentary, schematic view in elevation, verysimilar to FIGURE 2, but showing in detail the dotfing and drafting ofan illustrative fiber; and

FIGURE 6 is a simplified, fragmentary, schematic view in elevationshowing the structure and operation of another embodiment of the dofiingand drafting mechanism of the present invention.

In the embodiment of the invention illustrated in FIG- URES 1 through 5of the drawings, a conventional textile card is used and comprises aconventional rotatable main card cylinder It) which is used to providefor the normal carding of the fibers fed to the card whereby the fibersare disentangled and the bunches or tufts of fibers are separated moreor less into individual fibers. The initial attenuatin. of the fibersinto a generally aligned condition takes place on the surface of themain cylinder 16 and the individualized fibers are sparsely spread overthe rotating surface in an amount weighing but a few grains per squareyard.

These substantially individualized fibers which do not normallyconstitute a self-sustaining fibrous web are presented to and depositedon the surface of a dofiing cylinder 12 which rotates on a shaft 14mounted in bearings 16 secured to the card frame 18. The doifingcylinder 12 rotates at a much lower peripheral surface linear velocitythan the main cylinder 10, in accordance with standard practice. Thisvelocity differential, which may be varied as desired, creates acondensing of the individual fibers into a thin, fibrous carded webnormally weighing from about 30 grains to about 250, and preferably fromabout 60 to about grains per square yard, on the peripheral surface ofthe rotatable doffing cylinder 12.

As shown in FIGURE 3, the individual fibers which were hooked upon thepins of the card cylinder are pulled off those pins by the teeth of thedofiing cylinder and are deposited on the surface of the doffingcylinder in U- shaped or hook-shaped fashion. One end of the fiber liesin a leading or forwardly-directed position on the dofiing cylinder, andnormally the trailing portion is hooked reversely to form a U-shapedconfiguration, but occasionally it meanders rearwardly in various shapesand random configurations. (In FIGURE 3, the forward direction ofmovement of the dofiing cylinder corresponds to the downward directionin the drawing.)

When U-shaped, the lengths of the leading leg portion and trailing legportion vary from some shapes in which the trailing leg portion is verysmall and constitutes only a minor fraction of the total length of theindividual fiber to other shapes in which the trailing leg portion isalmost as long as the leading leg portion and thus constitutes almost50% of the total length of the individual fiber. When the trailingportion merely meanders rearwardly, the configurations are almostinfinite and defy any specific classification. In substantially allconfigurations, however, it is noted that one end of the fiber extendsforwardly more than the other portions of the fiber, and that portion ofthe fiber is thus the so-called leading end portion to be discussed ingreater detail hereinafter.

FIGURE 4 shows the same strip of fibrous web engaged with the pins ofthe doffing cylinder as is shown in FIG- URE 3. However, the web is nowshown at approximately the eight oclock position on the dofling cylinderof FIGURE 1. FIGURE 4 may be considered to be the result obtained byflopping FIGURE 3 over.

In FIGURE 4 one observes the same illustrative individual fibers as arecontained in FIGURE 3, except that they are now in the position occupiedby them after they have moved through substantially one-third of arevolution of a doffing cylinder from their positions shown in FIGURE 3.

The main cylinder and the dofiing cylinder 12 are conventional; the maincylinder being about 50 inches in outside diameter and about 45 inchesWide; and the doifing cylinder being about 26 or 27 inches in outsidediameter and also about 45 inches wide. The main cylinder and thedoifing cylinder are both covered with conventional card clothing,comprising a large number of pins which constitute protuberances actingtogether as a carrier surface, adapted to have fibers entwined with theprotuberances in slidable engagement therewith.

As seen in FIGURE 1, the top portions of the pins of the doifingcylinder are slanted in the opposite direction from the direction inwhich the leading free ends ofthe fibers slant which are intertwinedwith the pins as described above. (In the embodiment shown, the latterdirection is the direction of linear movement of the surface of thedoffing cylinder.) As a result, when a given fiber is slid off thefiber-carrying surface of the dofiing cylinder by the dofiing anddrafting mechanism 2% to be described below, the slidably restrainedtrailing portion of the fiber will not ordinarily be prematurely pulledoff the slanted top end of the pin or pins with which it is entwined. Itis important that the slidable engagement etween a fiber being doifedand drafted and the pin or pins of the dorfing cylinder with which it isengaged be maintained for as much of the period of time during whichthat fiber is being straightened out and pulled off the pins as ispossible. The longer the slidable engagement is continued, the longerthe period of positive drafting control at both ends of the fiber beingdrafted continues.

Immediately adjacent the doffing cylinder 12, and approximately at theposition where the fibrous web formed thereon is conventionally removedby the usual textile doffing comb, there is located a doffing anddrafting mechanism 20.

In the embodiment illustrated in FIGURE 1, the dotfing md draftingmechanism 20, as shown more particularly in FIGURE 2, comprises astationary, angular nose bar 22 having an elongated nose portion 24 anda reinforcing base portion 26. The reinforcing base portion 26strengthens and steadies the nose portion 24- but 'may be omitted whenthe nose portion 24 is sufficiently strong and steady by itself. Thenose bar 22 is adjustable so that the nose portion 24 thereof can becontrollably and accurately positioned at any desired angular relationship, or with any desired clearance, with respect to theperipheral surface of the dofi'lng cylinder 12. The point of closestproximity of the nose portion 24 to the peripheral surface of thedofiing cylinder 12 is referred to herein as the pickoff point P and isof importance for reasons to be made clear hereinafter.

An endless, flexible idofiing and drafting belt 3h is passed around thenose port-ion 24 and is then passed under a movable pressure member--inthe embodiment under discussion a rotatable, pressure nip roll 32-whichis adjustably positioned with respect to the nose portion 24 and theperipheral surface of the doffing cylinder 12. Due to the elongatedconfiguration of the nose portion 24-, the rotatable nip roll 32 is ableto be positioned not only very close to the nose portion 24 but also tothe adjacent pick-off point P on the peripheral surface of the doffercylinder 12.

A a result, the nip roll 32 is able to make initial contact with theflexible dofiing and drafting belt 30 at a point relatively close to thepick-off point P, as measured along the flexible belt 30. This point offirst contact between the rotatable nip roll 32 and the doffing anddrafting belt 30 is referred to herein as the nip poin N and is ofimportance for reasons to be made clear hereinafter.

The region through which the endless doffing and drafting belt passeswhich begins at about the pick-off point P in FIGURE 2 and extendsaround the nose portion 2 to nip point N may be characterized as thedofiing Zone. it will be noted that a portion of the guide means or nosebar 22 is located within the dofiing zone.

Because of its location, guide means or nose bar 22 acts to positiondotting and drafting belt 30, as it travels through the doffing zone, inclose'proximity to the carrier surface constituted of the pins ondoffing cylinder 12. At the same time, the guide means positions belt 36in pressing contact with the movable pressure member or nip roll 32. Theguide means presses the endless belt into first contact with the movablepressure member or nip roll 32 at nip point N, which is incloseproximity to the moving carrier surface 12, and as a result exposedfree ends of individual fibers engaged by the carrier surface aregrasped by the bite formed by the nip roll 32 and the endless belt 30. i

It is to be noted that the dofiing and drafting belt 3t) is so guided inits approach to the pick-off point that the space lying between the beltand the doffing cylinder gradually narrows down over a considerablearcuatev area to a relatively narrow throat. In this way, any fiberswhich protrude more or less from the Wire-toothed surface of the doffingcylinder are gradually pressed against such wire teeth into a morecompacted, denser web.

One advantage of such gradual pressing into a more compacted web is thatthe fiber-to-fiber cohesion is improved. Oonsequently, any short fiberswhich are prespacted web. As a consequence, therefore, in many cases ofshorter fibers, the surface of the dofiing cylinder restrains the fibersfor a short time only, or not at all, and the interfiber cohesion mayexert the major restraint.

The nip roll 32 is adjustably pressed against the movable doffing anddrafting belt 30 and has a surface linear velocity which issubstantially equal to the surface linem velocity of the belt. Thepressure of the nip roll 32 against the movable belt is such that adefinite arcuate length is formed in which the nip roll contacts thebelt and in which fibers positioned therebetween are pressed over asubstantial portion of their lengths. This increased length of pressingcontact on the fiber is vastly superior to the pressing contact obtainedby using two cylindrical tangentially positioned rolls having only arolling point contact on the fibers whereby slippage is possible andprobable.

The length of arcuate contact may be varied widely depending upon theparticular circumstances. In ,FIG- URE 2, the arcuate length coversabout of the circumference of the roll. A greater arcuate length wouldprovide greater =arcuate contact. Lesser arcuate lengths down to 15 or20 provide sufficient contact under many circumstances.

It is also to be noted that this arcuate contacting region is concavelycurved as compared to the convexly curved region where the fibers passover the nose bar 22. It is believed that such configuration assists inthe grasping of the fibers properly.

The downstream end of the arcuate contacting region may be identified aspoint N. The region through which endless belt 30 passes which extendsfrom point N to .N may be characterized as the gripping zone.

it will be noted that the arcuate path followed by drafting belt 36through the gripping zone has a center of curvature C which coincideswith the axis of nip roll 32. The path followed by the belt in passingthrough the gripping zone has a corresponding radius of curvature, whichis measured from point C to the surface of roll 32.

The dofiing and drafting belt 30 after passing under the rotatable niproll 32 passes upwardly over a driving rotatable guide roll 40. Thedriving rotatable guide roll 40 may be driven by any suitable drivingmeans such as an electric motor (not shown).

The doffing and drafting belt 30 is then directed downwardly and passesover an adjustable, rotatable, guiding and tensioning roll 42. Themounting of the rotatable, guiding and tensioning roll 42 is so arrangedthat it can be adjusted, as desired, in order to supply the desiredtension to the belt.

The dofiing and drafting belt 39 passes around a rotatable guide roll 44and is then directed upwardly over the nose portion 24 of the nose bar22. As can be seen, the belt is endless and moves in a continuous cycle,as described.

The operation of the dofiing and drafting mechanism is as follows. Thecarded web which is formed on the doffing cylinder is carried on theperiphery thereof around to the pick-oft point P. At this point, theelongated nose portion 24 positions the dofling and drafting belt 30with the desired clearance from the periphery of the doffing cylinder 12and the fibers are doffed or removed from the doffing cylinder andpositioned on the dotting and drafting belt 30 by adhesion and perhapsby electrostatic attraction. In this removal, it is to be noted that theleading ends of the fibers of the web on the dotfing cylinder 12 arepicked off first and are carried from the pick-off point P to the nippoint N and are then pressed against the dofiing and drafting belt 30 bythe rotatable nip roll 32.

By having the doffing and drafting belt 30 move with a linear velocitywhich is greater than the peripheral surface linear velocity of thedofiing cylinder, the individual fibers are drawn or drafted forwardlyand slid off the teeth or needles of the doifing cylinder 12 wherebythey are straightened and aligned with a considerably higher degree oforientation on the dotfing and drafting belt 30.

The ratio of the surface linear velocity of the doffing and draftingbelt to the surface linear velocity of the dofiing cylinder must begreater than 1 to 1 in order that drafting and increased alignment ofthe fibers is accomplished. In some instances, ratios as low as about1.1 to 1 have been used successfully depending primarily upon the natureand characteristics of the fibers involved. In most instances, ratios offrom about 1.5 to 1 to about 4 to 1 have been found preferable, withoptimum results being noted at about 3 to 1. Ratios higher than 4 to 1are utilizable within the principles of the present invention, withvalues of up to to 1 or higher being of use in special cases.

The nose portion 24 of the nose bar 22 so positions the dofling anddrafting belt 30 that the clearance between the belt and the dotfingcylinder 12 is maintained within closely controlled limits. Within thebroader aspects of the present invention, it has been found that thisclearance should be as small as physically possible and should be on theorder of from about 0.005 inch to about 0.150 inch for cotton or rayonfibers of typical lengths. Within the more commercial aspects of thepresent invention, it has been found, again with cotton and rayon fibersof typical lengths, that a narrower range of from about 0.007 inch toabout 0.040 inch is preferred.

The rotatable nip roll 32 is also adjustably positioned in such a waythat the clearance between its peripheral surface and the peripheralsurface of the dofiing cylinder 12 is a small as physically possible andis in the range of from about 0.005 inch to about 0.150 inch for thetypes of fibers just referred to. Within the more commercial aspects ofthe present invention, such clearance is preferably in the range of fromabout 0.007 inch to about 0.040 inch for fibers of the type indicated.

Due to the unusual elongated nature of the nose portion 24, the distancefrom the pick-off point P on the 'fibers of typical lengths.

doffing cylinder to the nip point N on the nip roll 32,

as measured along the flexible belt 30, is kept to a minimum. In thisway, positive removal of all the fibers from the doffing cylinder isobtained for all the fibers whose free leading ends extend outward fromthe cylinder far enough to be grasped between the bite at the nip pointN, and any tendency of the fibers to return to the dofiing cylinder 12as it passes beyond nip point N is reduced to a minimum.

The maximum distance between the pick-off point and the nip point shouldbe not more than about one-half the staple length of the fibers beingcarded. More specifically, it has been found that the distance from thefiber pick-01f point to the nip point should be from about 20% to about50% of the average staple length of the fibers. Within the morecommercial aspects of the present invention, however, from about 30% toabout 50% of the average staple length has been found preferable. Thesepercentages will be discussed in greater detail hereinafter and thescientific basis for such values will be made clear.

It is realized that the distance from the fiber pick-off point to thenip point may be decreased even further by providing a narrower and moreelongated nose portion 24. However, the requirements for adequatephysical strength of the nose portion prevent the making of the noseportion too thin. Additionally, the wear and tear on the clotting anddrafting belt increases as it is flexed more sharply over narrower noseportions whereby its service life is drastically reduced. It has beenfound that a nose portion with a controlling end portion having a radiusof from about inch to about W inch is satisfactory for best over-allperformance characteristics when cotton or rayon fibers of typicallengths are involved.

Nose portion 24 has a center of curvature C;., as shown in FIGURE 2. Thecorresponding radius of curvature is measured from point Cp to the endof the curved portion of the guide means or nose bar 22 around which theendless dofiing and drafting belt 30 moves as it passes through thedofiing zone into the gripping Zone.

The fact that the radius of curvature for the portion of the nose bar 22located in the dofiing zone is less than the radius of curvature of thepath followed by the endless belt 30 from point N to point N through thegripping zone makes the distance from nip point N to pick-off point Psmaller than has heretofore been achievable in the prior art. Similarly,the distance between the nip point N and pick-off point P is reduced bythe fact that the center of curvature C is closer to the carrier surfaceof the dofiing cylinder 12 than is the center of curvature O Thematerials of which the doffing and drafting belt and nip roll are madeare of importance. Substantially any suitable material is satisfactoryincluding metal, leather, rubber, plastic, fabric, film, etc. However,it is desired that the surface of the roll be made of a harder materialthan the belt, to improve the grip on the fibers during drafting. Ifincorrect materials are used, the nip roll will tend to slide on thedofiing and drafting belt and the advantages of the present inventionare lost.

The diameter of the nip roll is also a factor to be considered. If thenip roll is too small, there is a tendency for the fibers to lap or wraparound the nip roll rather than to stay with the dofling and draftingbelt. If the nip roll, however, is made too large, the distance betweenthe pick-off point P and the nip point N becomes too large and theadvantages of the present invention are lost. Within the more practicalaspects of the present invention, the diameter of the nip roll is in therange of from about inch to about 3 inches for cotton or rayonCommercially, the range for such fibers has been found to be preferablybetween 1 /1 inches and 2% inches.

The individual fibers of the fibrous web on the dofiing cylinder aredofied at the pick-off point P, are gripped between the dofiing anddrafting belt 30: and the rotatable nip roll 32 at the nip point N and,due to the higher linear velocity of the drafting belt 39, aresimultaneously drawn forwardly at a greater speed, and are drafted.

During this simultaneous doffing and drafting operation, an unusualadvantage of the present invention is noted. The fibers on the doifingcylinder are for the most part positioned thereon in a hooked orU-shaped configuration with the open end of the U facing forwardly inthe direction of movement of the doffing cylinder. In the case of thosefibers which are not hooked or U-shaped, there is nevertheless still aleading end which operates in the same Way as the end of the leading legof a U- shaped fiber. A simplified, diagrammatic showing of how fibershaving a U shape or other configuration such as just described may bedistributed in a typical portion of a card web is given in FIGURE 3 andalso in FIGURE 4. The following description, although specific withrespect to using a U-shaped fiber as the illustrative fiber neverthelessis generically applicable to all fibers of the web.

The lengths of the legs of the u shaped fibers are of all varyinglengths, depending to a large extent upon the manner in which they aretransferred from the main card cylinder and deposited on the dofiingcylinder. As a practical matter, the two legs of a U-shaped fiber willrarely, if ever, be exactly equal and consequently in practically everycase one leg of a U-shaped fiber is ahead of the other leg. As a result,it is this leading leg of the U-shaped fiber (or the leading end of anon-U- shaped fiber) which is first positioned on the flexible movablebelt 30 and first gripped by the pressure nip roll 32 and drawnforwardly in positive fashion.

FIGURE 5 illustrates four illustrative fibers: the first two fibers andF) as they approach the pick-off point P; the third (F), as it is beingpulled forwardly by the doffing and drafting belt 30 and the nip roll 32and aligned thereby with its trailing portion still being restrained onthe pins of the doffing cylinder; and the fourth (f after it has beendrafted and aligned and is moving forwardly over roll All. Fibers f andf would occupy substantially the position shown at the extreme right endof FIGURE 4, when observed by one looking at the doffing cylinder fromthe left hand side of FIGURE '1 or FIGURE 5 Since the movable belt 3%and nip roll 32 have a higher surface linear velocity than the doflingcylinder, as soon as they grasp the leading end of a fiber theyimmediately begain to draw the leading leg forwardly at an increasedvelocity and, since the base or trailing portion of the U- shaped fiberis hooked around a wire or a tooth on the dofiing cylinder, the shorterleg of the U-shaped fiber is gradually pulled or slid around that pointor tooth whereby it is ultimately drawn out as straight as possible,considering its inherent physical characteristics, and so positioned onthe drafting belt. In this way', the individual fibers are straightenedor aligned in the machine direction to a very high degree andconsiderably higher than previously possible.

It is immediately apparent that, in order to insure that each individualfiber of at least average length will be grasped between the bite formedby the dofiing and drafting belt and the pressure nip roll and will berestrained by the doffing cylinder at the same time, the maximumdistance from the piclooif point to the nip point must be no greaterthan about 50% of the length of the average individual fiber. Thisdistance will insure the positive control just described at both ends ofall fibers of at least average length (so long as the fiber forms nomore than one hook) even in the extreme case in which both legs of thebook are of substantially the same length.

A nip point to pick-0E point distance of less than 50% of the averagefiber length is, of course, preferred, and

it percentages down to about 20 or 25% are highly advantageous. Lessthan 20% is even more highly advantageous, but the physical weakening ofthe strength of the nose bar begins to be noted and deflection of thesupporting rolls and other members enters to disrupt the uniformity andcontinuity of the operation.

On the other hand, inasmuch as only a small percentage of the individualfibers are bent almost in half, and thus require a distance of no morethan 50% average fiber length from pick-off point to nip point, and,inasmuch as in many cases the shorter leg of the U-shaped fiber is onlyabout one-third of the total length of the individual fiber, rather thanabout half, it has been found that satisfactory drafting may actuallytake place if the distance from the pick-elf point to the nip point isincreased to about /3 or about 67% :of the average length of the fiberbeing treated. Not all of the fibers will be drafted and aligned withpositive control when such higher percentages are used, but this can betolerated in many cases where lower degrees of fiber orientation arepermissible.

The drafted and straightened fibers are carried forward on the movablebelt 3% over the driving roll 40 down over the tensioning roll 4-2. andare permitted to fall upon an inclined plate or conveyor 54 to be ledforward to be further processed as desired. In FIGURE 1, there is showna trumpet 52 which is used to form the fibrous web into a conventionalcylindrical sliver which passes between pressing rollers 54 and 56 andis then led forwardly by conveyor or other delivery means for furtherprocessing. Other devices than a trumpet 52 could be employed, or thefibrous web could be further processed in web form or in other shapes,as desired, and the trumpet 52 is employed to illustrate merely one ofmany devices which could be used.

Another embodiment of the dofiing and drafting mechanism of theinvention is shown in FIGURE 6. In that figure, the movable pressuremember of the embodiment described in detail above (rotatable nip roll32) is re placed by the endless belt 6% Endless belt 6%) passes aroundguide means 62 and adjustable rotatable guide and tensioning roll 64.Endless belts 3t} and 6%) move at substantially the same rate of speed.

The other guide rolls 4t 42 and 44 of the embodiment of FIGURE 6' arethe same as in the embodiment previously described. In addition, guidemeans or nose bar 22, with its nose portion 24, is the same as in theprevious embodiment.

It is seen that use of two belts permits bringing the nip point N evencloser to the fiber pick-off point P on the doffing cylinder 12 than wastrue with the embodiment employing one endless belt and a pressure niproll.

The material of which the endless belts 3t and 69 are formed should beor" different hardness, in order to produce the best grip on the fibersin the gripping Zone extending from point N to N.

The guide means 62 may be provided with openings 65 to assist indissipating the frictional heat produced by passage of the endless belt69 over the guide means. Other suitable lubricating and cooling meansmay also be employed to diminish and dissipate this heat of friction.

The guide means 62 has a radius of curvature greater than the radius ofcurvature of the portion of the nose bar 22 located in the doffing zone,with the attendant adv-antage of reduction in the distance from the nippoint N to the pick-off point P. The radius of curvature of the guidemeans 62 is measured from its face which is in contact with endless belt6% to center of curvature C The radius of curvature of the nose portion24 of guide means 22 is measured from the curved surface at the end ofthe nose portion to center of curvature C In the embodiment shown inFIGURE 6, the radius of curvature of the guide means 62 is constantthroughout the gripping zone. It may be desired to provide a curvaturethat is not constant for the path followed by .is substantially Zero.

the endless belts 3t) and 65) as they move through the gripping zone. Insuch case, the path will still have a general curvature which can beapproximated by drawing an arc through point N at one end of thegripping zone, another point near the middle of the zone, and point N atthe other end of the gripping zone. To attain the advantages of thisinvention, the general radius of curvature thus approximated must begreater than the radius of curvature of the curved portion of the guidemeans 22 within the doifiug zone.

It may also be desired to decrease the curvature of the path followed bythe belts of the gripping zone until it It will be recognized that sucha path could be considered as having an infinite radius of curvature.

Whether the movable pressure member of the dofling and draftingmechanism of this invention is a rotatable .nip roll or a rotatableendless belt, it is desirable to make the gripping zone at least as longas the longest fiber being doffed and drafted. A gripping zone of thislength insures positive control at the forward end of each fiber as itis straightened out while being slid off the fiber carrying surface.

No matter what the nature of the movable pressure member, the grippingzone formed by the pressing contact of that member against the endlessdoffing and drafting belt should have as large a radius of curvature asis consistent with the remainder of the mechanism. The more gradual thecurve of the path followed by the doffing and drafting belt through thegripping zone, the less the tendency will be toward fouling by theadhering of fibers to the movable pressure member.

The invention will be further illustrated in greater detail by thefollowing specific examples. It should be understood, however, thatalthough these examples may describe in particular detail some of themore specific features of the invention, they are given primarily forpurposes of illustration and the invention in its broader aspects is notto be construed as limited thereto.

Example I The starting fibrous material, as delivered by the dottingcylinder to the dotting and drafting belt, is a 45 inch-wide card web ofviscose rayon staple fibers, weighing about 75 grains per square yardand containing fibers having a substantially uniform length of about 1inch and a denier of about 1 /2. The peripheral surface linear velocityof the dofiing cylinder is yards per minute. The doffing cylinder iscovered with metallic clothing having 11 points per inch with 2.6 wrapsper inch of cylinder.

The fibrous web is transferred to a flexible movable dotfing anddrafting belt which passes over a nose bar and is accurately spaced0.005 inch from the peripheral surface of the doffing cylinder. Thedofi'ing and drafting belt has a peripheral surface linear velocity of22 yards per minute. This is equivalent to a 1.1 to 1 ratio (belt todofiing cylinder). The nose portion of the nose bar is about inch thickand the radius of the controlling end is about inch. The belt thenpasses under a nip roll having a diameter of 2 inches. The distance fromthe pick-off point the doffing cylinder to the nip point on the niproll, as measured along the flexible belt, is about /2 inch, or 50% ofthe average staple length of the fibers.

Examination of the fibrous web, after it has been removed from theflexible belt, reveals that the drafted web has a weight of about 6 8grains per square yard and a much higher degree of fiber orientationthan that present in a similar fibrous web prepared from similarmaterials on similar equipment but removed from the doting cylinder by aconventional domng comb.

The degree of fiber orientation of the fibrous web on the doflingcylinder is about 70%; the degree of fiber orientation of the draftedweb is about 85%. The web is well suited for further processing andultimate spinning into yarn.

12 Example 11 The starting fibrous material, as delivered by theclotting cylinder to the dofiing and drafting belt, is a 45 inch-widecard web of viscose rayon staple fibers, weighing about grains persquare yard and containing fibers having a substantially uniform lengthof about 1% inches and a denier of about 1 /2. The peripheral surfacelinear velocity of the doffing cylinder is 20 yards per minute. Thedoffing cylinder is covered with metallic clothing having 11 points perinch with 26 wraps per inch of cylinder.

The fibrous web is transferred to a flexible movable doffing anddrafting belt which passes over a nose bar and is accurately spaced0.007 inch from the peripheral surface of the dofiing cylinder. Thedofiing and drafting belt has a peripheral surface linear velocity of 25yards per minute. This is equivalent to a 1.25 to 1 ratio (belt todofiing cylinder). The nose portion of the nose bar is about 5 inchthick and the radius of the controlling end is about inch. The belt thenpasses under a nip roll having a diameter of 2 inches. The distance fromthe pick-off point on the dofiing cylinder to the nip point on the niproll, as measured along the flexible belt, is about /2 inch, or 40% ofthe average staple length of the fibers.

Examination of the fibrous web reveals that the drafted web has a weightof about 64 grains per square yard and a much higher degree of fiberorientation than that present in a similar fibrous web prepared fromsimilar materials on similar equipment but removed from the doffingcylinder by a conventional doffing comb.

The degree of fiber orientation of the fibrous web on the doffingcylinder is about 70%; the degree of fiber orientation of the draftedweb is about The web is well suited for further processing and ultimatespinning into yarn.

Example III The starting fibrous material, as delivered by the dottingcylinder to the doffing and drafting belt, is a 45 inch-wide card web ofviscose rayon staple fibers, weighing about grains per square yard andcontaining fibers having a substantially uniform length of about 1%inches and a denier of about 1 /2. The peripheral surface linearvelocity of the dotting cylinder is 20 yards per minute. The dofiingcylinder is covered with metallic clothing having 11 points per inchwith 26 wraps per inch of cylinder.

The fibrous web is transferred to a flexible movable dotling anddrafting belt which passes over a nose bar and is accurately spaced0.010 inch from the peripheral surface of the dofling cylinder. Thedofling and drafting belt has a peripheral surface linear velocity of 30yards per minute. This is equivalent to a 1.5 to 1 ratio (belt todotfing cylinder). The nose portion of the nose bar is about /4 inchthick and the radius of the controlling end is about ,5; inch. The beltthen passes under a nip roll having a diameter of 2 inches. The distancefrom the pick-off point on the doifing cylinder to the nip point on thenip roll, as measured along the flexible belt is about /2 inch, or 32%of the average staple length of the fibers.

Examination of the fibrous web reveals that the drafted web has a weightof about 67 grains per square yard and a much higher degree of fiberorientation than that present in a similar fibrous web prepared fromsimilar materials on similar equipment but removed from the dofiingcylinder by a conventional doffing comb. The degree of fiber orientationof the fibrous web on the dofiing cylinder is about 70%; the degree offiber orientation of the drafted web is about 92%. The web is wellsuited for further processing and ultimate spinning into yarn.

Example IV The starting fibrous material, as delivered by the dofiingcylinder to the dofiing and drafting belt, is a 45 inch-wide card web ofcotton staple fibers having an average staple length of about 1 inch andweighing about 100 grains per web is about 90%.

13 square yard. The peripheral surface linear velocity of the doflingcylinder is yards per minute. The domng cylinder is covered withmetallic clothing having 11 points per inch with 26 wraps per inch ofcylinder.

The fibrous web is transferred to a flexible movable drafting belt whichpasses over a nose bar and is accurately spaced 0.015 inch from theperipheral surface of the doffing cylinder. The drafting belt has aperipheral surface linear velocity of 30 yards per minute. This isequivalent to a 1.5 to 1 ratio (belt to doffingcylinder). The noseportion of the nose bar is about A inch thick and the radius of thecontrolling end is about inch. The belt then passes under a nip rollhaving a diameter of 2 inches. The distance from the pick-off point onthe doffing cylinder to the nip point on the nip roll, as measured alongthe flexible belt, is about inch or 37% of the average staple length ofthe fibers.

Examination of the fibrous web reveals that the drafted web has a weightof about 67 grains per square yard and a much higher degree of fiberorientation than that present in a similar fibrous web prepared fromsimilar materials on similar equipment but removed from the doffingcylinder by a conventional dofiing comb. The degree of fiber orientationof the fibrous web on the doffing cylinder is about 70%; the degree offiber orientation of the drafted The web is well suited for furtherprocessing and ultimate spinning into yarn.

Example V The starting fibrous material, as delivered by the doifingcylinder to the drafting belt, is a inch-wide card web weighing about100 grains per square yard and containing by weight of cotton staplefibers having an average length of about 1% inches and 50% by weight ofviscose rayon staple fibers having a length of about 19 inches and adenier of about 1 /2. The peripheral surface linear velocity of thedoffing cylinder is 20 yards per minute. The doffing cylinder is coveredwith metallic clothing having 11 points per inch with 26 wraps per inchof cylinder.

The fibrous web is transferred to a flexible movable drafting belt whichpasses over a nose bar and is accurately spaced 0.012 inch from theperipheral surface of the doffing cylinder. The drafting belt has aperipheral surface linear velocity of 30 yards per minute. This isequivalent to a 1.5 to 1 ratio (belt to doffing cylinder). The noseportion of the nose bar is about A inch thick and the radius of thecontrolling end is about inch. The belt then passes under a nip rollhaving a diameter of 2 inches. The distance from the pick-off point tothe nip point is about inch or about 40% of the average staple length ofthe fibers.

Examination of the fibrous web reveals that the drafted web has a weightof about 67 grains per square yard and a much higher degree of fiberorientation than that pres ent in a similar fibrous web prepared fromsimilar materials on similar equipment but removed from the deffingcylinder by a conventional dofiing comb. The degree of fiber orientationof the fibrous web on the doffing cylinder is about 70%; the degree offiber orientation of the drafted web is about 90%. The web is wellsuited for further processing and ultimate spinning into yam.

Although several specific examples of the inventive concept have beendescribed, the same should not be construed as limited thereby nor tothe specific features mentioned therein but to include various otherequivalent features as set forth in the claims appended hereto. It isunderstood that any suitable changes, modifications and variations maybe made without departing from the spirit and scope of the invention.

What is claimed is:

1. The method of doffing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with 1d ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface and providing a stationary support for said movingsurface to control the point of closest proximity between said movingsurface and said rotating surface, said stationary support contactingsaid moving surface substantially only at said point of closestproximity;

(0) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface whereby theends of the fibers contacting the moving surface are gradually inclinedforwardly and drawn forwardly in the direction of movement of the movingsurface;

(a') gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof to form a more compacted web havingincreased fiberto-fiber cohesion and capable of being restrained morepositively on the surface of said rotating sur face;

(e) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

(7) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said rotatingsurface; and

(g) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to-fiber cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of the web is increased.

2. The method of doffing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(12) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface and providing a stationary support for said movingsurface to control the point of closest proximity between said movingsurface and said rotating surface, said stationary support contactingsaid moving surface substantially only at said point of closestproximity;

(0) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface whereby theends of the fibers contacting the moving surface are gradually inclinedforwardly and drawn forwardly in the direction of movement of the movingsurface;

(d) gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof to form a more compacted web havingincreased fiberto-fiber cohesion and capable of being restrained morepositively on the surface of said rotating surface;

(e) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

(f) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region spaced from said rotating surface by adistance less than about one-half the average length of the fibers beingdoffed and drafted; and

(g) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to-fibcr cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of the web is increased.

3. The method of dofiing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface at a point well in advance of a hereinaftermentionedpick-off point and providing a stationary support for said movingsurface to control the spatial relationship of said moving surface andsaid rotating surface at said pick-01f point, said stationary supportcontacting said moving surface substantially only at said pick-offpoint;

(c) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface whereby theends of the fibers contacting the moving surface are gradually inclinedforwardly and drawn forwardly in the direction of movement of the movingsurface as they approach the hereinafter-mentioned pick-ofi point;

(d) gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof immediately preceding thehereinafter-mentioned pick-off point to form a more compacted web havingincreased fiber-to-fiber cohesion and capable of being restrained morepositively on the surface of said rotating surface;

(6) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface ata pick-off point which is the point of closest proidmity of the movingsurface to the rotating surface;

(1) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said pickoifpoint; and

(g) drawing said leading free ends of the individual fibers away fromsaid pick-off point, at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous Web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to-fiber cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of r the web is increased.

4. The method of dofiing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

([1) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface at a point well in advance of a hereinaftermentionedpick-off point and providing a stationary support for said movingsurface to control the spatial relationship of said moving surface andsaid rotating surface at said pick-d point, said stationary support 16contacting said moving surface substantially only at said pick-offpoint;

(c) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface whereby theends of the fibers contacting the moving surface are gradually inclinedforwardly and drawn forwardly in the direction of movement of the movingsurface as they approach the hereinafter-mentioned pick-off point;

(d) gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof immediately preceding thehereinafter-mentioned pick-off point to form a more compacted web havingincreased fiber-to-fiber cohesion and capable of being restrained morepositively on the surface of said rotating surface;

(e) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said movable surfaceat a pick-off point which is the point of closest proximity of themoving surface to the rotating surface;

(1) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region spaced from said pick-off point by adistance less than about one-half the average length of the fibers beingdoifed and drafted; and

(g) drawing said leading free ends of the individual fibers away fromsaid pick-off point, at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to'fiber cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of the web is increased.

5. Apparatus for dofiing a web of fibers from a rotatable surface andsubstantially simultaneously drafting the same which comprises:

(a) a rotatable cylindrical surface for carrying a web of fibers withends of the fibers extending outwardly beyond the periphery of therotatable cylindrical surface;

(b) a movable surface movable in a closed path adjacent said rotatablecylindrical surface;

(c) guide means for gradually bringing said movable surface into aposition of close proximity to said rotatable cylindrical surfacewhereby the protruding ends of the fibers contact the movable surface ata point well in advance of a hereinafter-mentioned pick-off point, saidguide means including stationary means contacting said movable surfacesubstantially only at said pick-off point;

(d) means within said closed path to drive said movable surface at alinear speed greater than the linear speed of the rotatable cylindricalsurface whereby the ends of the fibers contacting the movable surfaceare gradually inclined forwardly and drawn forwardly in the direction ofmovement of the movable surface as they approach thehereinafter-mentioned pick-off point, said fibers bcing graduallypressed by said movable surface against an arcuate area of the rotatablecylindrical surface to form a more compacted web thereon havingincreased fiber-to-fibcr cohesion, said movable surface being broughtinto such close proximity to said rotatable cylindrical surface as toprovide for fiber transfer from said rotatable cylindrical surface tosaid movable surface at a pick-off point which is the point of closestproximity of said movable surface to said rotatable cylindrical surface;and

(e) means cooperating with said movable surface to grasp the leadingfree ends of the advancing individual fibers of the compacted webcarried on said movable surface at a region in close proximity to saidpick-01f point,

said driving means in direct contact with said movable surface drivingthe same and drawing said leading free ends of the individual fibersaway from said pick-off point with a linear speed greater than thesurface linear speed of the rotatable cylindrical surface, Whilemaintaining substantially the uniformity of the fiber weightdistribution of the fibrous web and while restraining the trailing endsof said fibers by sliding engagement with said rotatable cylindricalsurface and by the increased fiber-to-fiber cohesion, whereby theindividual fibers are straightened and their degree of orientation inthe long direction of the web is increased.

6. Apparatus for doffing a web of fibers from a rotatable dofiingcylinder and substantially simultaneously drafting the same whichcomprises:

(a) a rotatable dofiing cylinder for carrying a web of fibers with endsof the fibers extending outwardly beyond the periphery of the doifingcylinder;

(b) a movable dofiing and drafting belt movable in a closed pathadjacent said rotatable dofiing cylinder;

() guide means for gradually bringing said movable doffing and draftingbelt into a position of close proximity to said rotatable doffingcylinder whereby the protruding ends of the fibers contact the movabledofiing and drafting belt at a point well in advance of ahereinafter-mentioned pick-off point, said guide means includingstationary means contacting said movable dofling and drafting beltsubstantially only at said pick-olf point;

(d) means within said closed path to drive said movable doffing anddrafting belt at a linear speed greater than the linear speed of therotatable dolfing cylinder whereby the ends of the fibers contacting themovable doffing and drafting belt are gradually inclined forwardly anddrawn forwardly in the direction of movement of the movable dofiing anddrafting belt as they approach the hereinaftermentioned pick-off point,said fibers being gradually pressed by said movable doffing and draftingbelt against an arcuate area of the rotatable doffing cylinder to form amore compacted web thereon having increased fiber-to-fiber cohesion,said movable doffing and drafting belt being brought into such closeproximity to said rotatable dofiing cylinder as to provide for fibertransfer from said rotatable dofiing cylinder to said movable doffingand drafting belt at a pick-off point which is the point of closestproximity of said movable dofiing and drafting belt to said rotatabledoffing cylinder; and

(e) means cooperating with said movable dotfing and drafting belt tograsp the leading free ends of the advancing individual fibers of thecompacted web carried on said movable dofiing and drafting belt at aregion in close proximity to said pick-off point,

said driving means in contact with said movable dofiing and draftingbelt driving the same and drawing said leading free ends of theindividual fibers away from said pick-off point with a linear speedgreater than the surface linear speed of the rotatable doffing cylinder,while maintaining substantially the uniformity of the fiber weightdistribution of the fibrous web and while restraining the trailing endsof said fibers by sliding engagement with said rotatable doffingcylinder and by the increased fiber-to-fiber cohesion, whereby theindividual fibers are straightened and their degree of orientation inthe long direction of the web is increased.

7. The method of doffing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface and providing a stationary support for said movingsurface to control the point of closet proximity between said movingsurface and said rotating surface, said stationary support contactingsaid moving surface substantially only at said point of closestproximity;

(c) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface by a ratioof from about 1.5 to 1 to about 4 to 1, whereby the ends of the fiberscontacting the moving surface are gradually inclined forwardly and drawnforwardly in the direction of movement of the moving surface;

(d) gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof to form a more compacted web havingincreased fiber-to-fiber cohesion and capable of being restrained morepositively on the surface of said rotating surface;

(e) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

(f) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said rotatingsurface; and

(g) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, said speeds having a ratio of fromabout 1.5 to l to about 4 to 1, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-tofiber cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of the web is increased.

8. The method of dofiing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) gradually guiding a moving surface movable in a closed path towardsaid rotating surface whereby the protruding ends of the fibers contactthe moving surface and providing a stationary support for said movingsurface to control the point of closest proximity between said movingsurface and said rotating surface, said stationary support contactingsaid moving surface substantially only at said point of closestproximity;

(0) driving said moving surface from within said closed path at a linearspeed greater than the linear speed of the rotating surface by a ratioof about 3 to 1 whereby the ends of the fibers contacting the movingsurface are gradually inclined frowardly and drawn forwardly in thedirection of movement of the moving surface;

(d) gradually pressing the fibers of said web against said rotatingsurface over an arcuate area thereof to form a more compacted Web havingincreased fiberto-fiber cohesion and capable of being restrained morepositively on the surface of said rotating surface;

(e) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

( grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said rotatingsurface; and

(g) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to-fiber cohesion,whereby the individual fibers are straightened and their degree oforientation in the long direction of the web is increased.

9. The method of doffing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) causing said web of fibers by the rotation of said rotating surfaceto enter a zone extending over a considerable arcuate area of saidrotating surface and narrowing gradually throughout the extent of saidarea toward a throat, said zone being defined on one side by saidrotating surface and on the opposite side by a moving surface movable ina closed path traveling in the same direction as the rotating surface attheir points of adjacency and at a greater linear speed, whereby ends offibers protruding from said rotating surface and engaged by said movingsurface are inclined forwardly in the direction of fiber travel as saidfibers move from the entrance end of said zone to the throat thereof;

(c) driving said moving surface from within said closed path;

(d) gradually pressing the fibers of said web against said rotatingsurface over said considerable arcuate area thereof as said fibers movetowards said throat to form a more compacted web having increasedfiber-to-fiber cohesion and capable of being restrained more positivelyon the surface of said rotating surface;

(2) providing a stationary support for said moving surface to controlthe point of closest proximity between said moving surface and saidrotating surface, said stationary support contacting said moving surfacesubstantially only at said point of closest proximity;

(f) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

(g) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said rotatingsurface; and

(/1) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, while maintaining substantially theuniformity of the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiber-to-fiber cohesion,whereby the individual fibers are drawn forwardly and straightened andtheir degree of orientation in the long direction of the web isincreased.

10, The method of dofiing a web of fibers from a rotating surface andsubstantially simultaneously drafting the same which comprises:

(a) carrying a web of fibers on a rotating surface with ends of thefibers protruding outwardly beyond the periphery of the rotatingsurface;

(b) causing said web of fibers by the rotation of said rotating surfaceto enter a zone extending over a considerable arcuate area of saidrotating surface and narrowing gradually throughout the extent of saidarea toward a throat, said zone being defined on one side by saidrotating surface and on the opposite side by a moving surface movable ina closed path traveling in the same direction as the rotating surface attheir points of adjacency and at a greater linear speed by a ratio offrom about 1.5 to 1 to about 4 to 1, whereby ends of fibers protrudingfrom said rotating surface and engaged by said moving surface areinclined forwardly in the direction of fiber travel as said fibers movefrom the entrance end of said zone to the throat thereof;

(0) driving said moving surface from within said closed path;

(d) gradually pressing the fibers of said web against said rotatingsurface over said considerable arcuate area thereof as said fibers movetowards said throat to form a more compacted web having increasedfiber-to-fiber cohesion and capable of being restrained more positivelyon the surface of said rotating surface;

(e) providing a stationary support for said moving surface to controlthe point of closest proximity between said moving surface and saidrotating surface, said stationary support contacting said moving surfacesubstantially only at said point of closest proximity;

(f) transferring the leading free ends of individual fibers of thecompacted web carried by said rotating surface to said moving surface;

(g) grasping the leading free ends of the individual fibers carried bysaid moving surface at a region in close proximity to said rotatingsurface; and

(h) drawing said leading free ends of the individual fibers away fromsaid rotating surface at a linear speed greater than the linear speed ofthe fibers on said rotating surface, said speeds having a ratio of from1.5 to l to about 4 to 1, while maintaining substantially the uniformityof the fiber weight distribution of the fibrous web and whilerestraining the trailing ends of said fibers by sliding engagement withthe rotating surface and by said increased fiberto-fiber cohesion,whereby the individual fibers are drawn forwardly and straightened andtheir degree of orientation in the long direction of the web isincreased.

References Cited in the file of this patent UNITED STATES PATENTS1,422,581 Laurency et al July 11, 1922 1,862,542 Laurency June 14, 1932FOREIGN PATENTS 1,127,219 France Aug. 6, 1956 255 Great Britain of 1853593 Great Britain of 1865 3,168 Great Britain of 1869

1. THE METHOD OF DOFFING A WEB OF FIBERS FROM A ROTATING SURFACE ANDSUBSTANTIALLY SIMULTANEOUSLY DRAFTING THE SAME WHICH COMPRISES: (A)CARRYING A WEB OF FIBERS ON A ROTATING SURFACE WITH ENDS OF THE FIBERSPROTRUDING OUTWARDLY BEYOND THE PERIPHERY OF THE ROTATING SURFACE; (B)GRADUALLY GUIDING A MOVING SURFACE MOVABLE IN A CLOSED PATH TOWARD SAIDROTATING SURFACE WHEREBY THE PROTRUDING ENDS OF THE FIBERS CONTACT THEMOVING SURFACE AND PROVIDING A STATIONARY SUPPORT FOR SAID MOVINGSURFACE TO CONTROL THE POINT OF CLOSEST PROXIMITY BETWEEN SAID MOVINGSURFACE AND SAID ROTATING SURFACE, SAID STATIONARY SUPPORT CONTACTINGSAID MOVING SURFACE SUBSTANTIALLY ONLY AT SAID POINT OF CLOSESTPROXIMITY; (C) DRIVING SAID MOVING SURFACE FROM WITHIN SAID CLOSED PATHAT A LINEAR SPEED GREATER THAN THE LINEAR SPEED OF THE ROTATING SURFACEWHEREBY THE ENDS OF THE FIBERS CONTACTING THE MOVING SURFACE AREGRADUALLY INCLINED FORWARDLY AND DRAWN FORWARDLY IN THE DIRECTION OFMOVEMENT OF THE MOVING SURFACE; (D) GRADUALLY PRESSING THE FIBERS OFSAID WEB AGAINST SAID ROTATING SURFACE OVER AN ARCUATE AREA THEREOF TOFORM A MORE COMPACTED WEB HAVING INCREASED FIBERTO-FIBER COHESION ANDCAPABLE OF BEING RESTRAINED MORE POSITIVELY ON THE SURFACE OF SAIDROTATING SURFACE; (E) TRANSFERRING THE LEADING FREE ENDS OF INDIVIDUALFIBERS OF THE COMPACTED WEB CARRIED BY SAID ROTATING SURFACE TO SAIDMOVING SURFACE; (F) GRASPING THE LEADING FREE ENDS OF THE INDIVIDUALFIBERS CARRIED BY SAID MOVING SURFACE AT A REGION IN CLOSE PROXIMITY TOSAID ROTATING SURFACE; AND (G) DRAWING SAID LEADING FREE ENDS OF THEINDIVIDUAL FIBERS AWAY FROM SAID ROTATING SURFACE AT A LINEAR SPEEDGREATER THAN THE LINEAR SPEED OF THE FIBERS ON SAID ROTATING SURFACE,WHILE MAINTAINING SUBSTANTIALLY THE UNIFORMITY OF THE FIBER WEIGHTDISTRIBUTION OF THE FIBROUS WEB AND WHILE RESTRAINING THE TRAILING ENDSOF SAID FIBERS BY SLIDING ENGAGEMENT WITH THE ROTATING SURFACE AND BYSAID INCREASED FIBER-TO-FIBER COHESION, WHEREBY THE INDIVIDUAL FIBERSARE STRAIGHTENED AND THEIR DEGREE OF ORIENTATION IN THE LONG DIRECTIONOF THE WEB IS INCREASED.
 5. APPARATUS FOR DOFFING A WEB OF FIBERS FROM AROTATABLE SURFACE AND SUBSTANTIALLY SIMULTANEOUSLY DRAFTING THE SAMEWHICH COMPRISES: (A) A ROTATABLE CYLINDRICAL SURFACE FOR CARRYING A WEBOF FIBERS WITH ENDS OF THE FIBERS EXTENDING OUTWARDLY BEYOND THEPERIPHERY OF THE ROTATABLE CYLINDRICAL SURFACE; (B) A MOVABLE SURFACEMOVABLE IN A CLOSED PATH ADJACENT SAID ROTATABLE CYLINDRICAL SURFACE;(C) GUIDE MEANS FOR GRADUALLY BRINGING SAID MOVABLE SURFACE INTO APOSITION OF CLOSE PROXIMITY TO SAID ROTATABLE CYLINDRICAL SURFACEWHEREBY THE PROTRUDING ENDS OF THE FIBERS CONTACT THE MOVABLE SURFACE ATA POINT WELL IN ADVANCE OF A HEREINAFTER-MENTIONED PICK-OFF POINT, SAIDGUIDE MEANS INCLUDING STATIONARY MEANS CONTACTING SAID MOVABLE SURFACESUBSTANTIALLY ONLY AT SAID PICK-OFF POINT; (D) MEANS WITHIN SAID CLOSEDPATH TO DRIVE SAID MOVABLE SURFACE AT A LINEAR SPEED GREATER THAN THELINEAR SPEED OF THE ROTATABLE CYLINDRICAL SURFACE WHEREBY THE ENDS OFTHE FIBERS CONTACTING THE MOVABLE SURFACE ARE GRADUALLY INCLINEDFORWARDLY AND DRAWN FORWARDLY IN THE DIRECTION OF MOVEMENT OF THEMOVABLE SURFACE AS THEY APPROACH THE HEREINAFTER-MENTIONED PICK-OFFPOINT, SAID FIBERS BEING GRADUALLY PRESSED BY SAID MOVABLE SURFACEAGAINST AN ARCUATE AREA OF THE ROTATABLE CYLINDRICAL SURFACE TO FORM AMORE COMPACTED WEB THEREON HAVING INCREASED FIBER-TO-FIBER COHESION,SAID MOVABLE SURFACE BEING BROUGHT INTO SUCH CLOSE PROXIMITY TO SAIDROTATABLE CYLINDRICAL SURFACE AS TO PROVIDE FOR FIBER TRANSFER FROM SAIDROTATABLE CYLINDRICAL SURFACE TO SAID MOVABLE SURFACE AT A PICK-OFFPOINT WHICH IS THE POINT OF CLOSEST PROXIMITY OF SAID MOVABLE SURFACE TOSAID ROTATABLE CYLINDRICAL SURFACE; AND (E) MEANS COOPERATING WITH SAIDMOVABLE SURFACE TO GRASP THE LEADING FREE ENDS OF THE ADVANCINGINDIVIDUAL FIBERS OF THE COMPACTED WEB CARRIED ON SAID MOVABLE SURFACEAT A REGION IN CLOSE PROXIMITY TO SAID PICK-OFF POINT, SAID DRIVINGMEANS IN DIRECT CONTACT WITH SAID MOVABLE SURFACE DRIVING THE SAME ANDDRAWING SAID LEADING FREE ENDS OF THE INDIVIDUAL FIBERS AWAY FROM SAIDPICK-OFF POINT WITH A LINEAR SPEED GREATER THAN THE SURFACE LINEAR SPEEDOF THE ROTATABLE CYLINDRICAL SURFACE, WHILE MAINTAINING SUBSTANTIALLYTHE UNIFORMITY OF THE FIBER WEIGHT DISTRIBUTION OF THE FIBROUS WEB ANDWHILE RESTRAINING THE TRAILING ENDS OF SAID FIBERS BY SLIDING ENGAGEMENTWITH SAID ROTATABLE CYLINDRICAL SURFACE AND BY THE INCREASEDFIBER-TO-FIBER COHESION, WHEREBY THE INDIVIDUAL FIBERS ARE STRAIGHTENEDAND THEIR DEGREE OF ORIENTATION IN THE LONG DIRECTION OF THE WEB ISINCREASED.